Thermodynamic Analysis of Resources Used in Manufacturing Processes

TLDR

The rise in material and energy intensity per unit mass in manufacturing has been driven by the demand for precise small‑scale devices and enabled by stable, declining material and energy prices. This study applies a thermodynamic framework, including exergy analysis, to characterize and promote efficient resource use across manufacturing processes for sustainable enterprise. The authors analyze 20 processes—from conventional machining, casting, and injection molding to advanced EDM, abrasive waterjet, and vapor‑phase semiconductor fabrication—using thermodynamic metrics to assess material and energy conversion. Results show that material and energy intensity has increased by at least six orders of magnitude over decades, largely due to new processes, and that exergy analysis pinpoints resource losses, guiding redesign for greater efficiency.

Abstract

In this study we use a thermodynamic framework to characterize the material and energy resources used in manufacturing processes. The analysis and data span a wide range of processes from “conventional” processes such as machining, casting, and injection molding, to the so-called “advanced machining” processes such as electrical discharge machining and abrasive waterjet machining, and to the vapor-phase processes used in semiconductor and nanomaterials fabrication. In all, 20 processes are analyzed. The results show that the intensity of materials and energy used per unit of mass of material processed (measured either as specific energy or exergy) has increased by at least 6 orders of magnitude over the past several decades. The increase of material/energy intensity use has been primarily a consequence of the introduction of new manufacturing processes, rather than changes in traditional technologies. This phenomenon has been driven by the desire for precise small-scale devices and product features and enabled by stable and declining material and energy prices over this period. We illustrate the relevance of thermodynamics (including exergy analysis) for all processes in spite of the fact that long-lasting focus in manufacturing has been on product quality—not necessarily energy/material conversion efficiency. We promote the use of thermodynamics tools for analysis of manufacturing processes within the context of rapidly increasing relevance of sustainable human enterprises. We confirm that exergy analysis can be used to identify where resources are lost in these processes, which is the first step in proposing and/or redesigning new more efficient processes.